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Pass Green Reflect Red dichroic mirror as an infrared filter

thebouljello

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I want to make a rg yellow laser by combining 650 and 532nm beams with a pass green reflect red dichroic mirror. Can this mirror double as an ir filter for the 532nm laser or will the ir be reflected? Thanks.
 



diachi

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I want to make a rg yellow laser by combining 650 and 532nm beams with a pass green reflect red dichroic mirror. Can this mirror double as an ir filter for the 532nm laser or will the ir be reflected? Thanks.

It's going to depend on the mirror - you'd either have to test it or get a transmission/reflection graph from the manufacturer that shows wavelength vs % transmitted/% reflected.
 
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thebouljello

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I bought it on ebay and there were no details for wavelengths other than 532 and 650. I would just assume that it does not filter ir to be safe.
 
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Can you post links to what you bought? Which type of build were you planning. I am also interested in a similar build.
 

thebouljello

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You can add a star cap, but it'll split the green and red back into individual green and red beams. ;)
I wonder what it would look like. I have seen projectors with red and green lasers where the red and green are clearly split. In some of them, there are faint traces of yellow beams.
 

diachi

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I wonder what it would look like. I have seen projectors with red and green lasers where the red and green are clearly split. In some of them, there are faint traces of yellow beams.
Something like this:



May still be some hints of yellow, but the red and green will split apart - shorter wavelengths diffract less than longer wavelengths. To get a true yellow out of a diffraction grating (Star cap, same thing) you'd need to use a true yellow laser - not two lasers combined.
 

thebouljello

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Something like this:



May still be some hints of yellow, but the red and green will split apart - shorter wavelengths diffract less than longer wavelengths. To get a true yellow out of a diffraction grating (Star cap, same thing) you'd need to use a true yellow laser - not two lasers combined.
I hope the color in my build turns out like the picture. I find it interesting that the color separation is a result of diffraction of longer wavelengths.
 




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